This invention relates generally to gas-insulated equipment, and more particularly to a spacer mount for use in gas insulated transmission lines.
Gas insulated transmission lines are generally comprised of an elongated conductor which is supported centrally within a cylindrical grounded housing by means of spaced insulator supports. The interior of the outer grounded conductor is then filled with a suitable gas having desired dielectric characteristics, such as sulfur hexafluoride under pressure. The transmission line is then operated at extremely high voltages, for example, 500KV. The outer housings of the transmission line have generally small diameters, and thus create exceptionally high electric fields within the interior of the gas-filled housing. It is also known to provide conductive particle traps along the length of the transmission line, which are formed by low field intensity regions which will tend to trap conducting or semi-conducting particles once these particles reach the low field region.
Because of the high fields present within the outer housing, and because of the relatively lower dielectric strength of the insulator support, it is important to mount the insulator supports within the outer housing in such a way so as to provide an optimal electric field distribution adjacent the insulator support. This is likewise important when the insulator support not only functions to physically support the inner conductor within the outer housing, but also when these supports are utilized to provide gas tight or semi-gas tight seals between adjacent sections of the transmission line. The optimum spacer mount should be inexpensive, gas tight, electrically functional, and capable of being practically assembled. Additionally, it is desirable to minimize the number of external seals required within the line, and to avoid the necessity of utilizing flanges for joining members together.